Petterson, 38, of Waterhouse Lane, Southampton, denies causing death by careless driving after the 48-year-old cyclist died on Mountbatten Way.

Mr Irving, from Wimborne, Dorset, died of multiple injuries when he fell from his Giant bike on the busy commuter route at 8.43am on December 17, 2012.

PC Wilson told the court how detailed investigations of the crash site and Petterson’s white Ford Transit minibus suggested the vehicle’s nearside wing mirror hit Mr Irving’s right armor elbow and brushed against his handlebars.

He told the court how calculations suggested the angle of the low sun on that morning and moisture on the road was likely to cause a glare, but said it was difficult to replicate road conditions on any given day.

He admitted it may have made it difficult for drivers to see when they came over the brow of the hill but said Petterson took at least 17 seconds from joining the road from Waterhouse Lane to the crash site and should have spotted other vehicles ahead moving out to overtake the cyclist.

The court heard how CCTV images earlier in the route showed that Mr Irving’s rucksack and the way he leaned forward while riding obscured a large part of his orange luminous biking jacket.

Under cross-examination PC Wilson admitted that coming over the brow of the hill it would have been “virtually impossible” to see Mr Irving and he may have “blended into the background”.

Mark Florida James, for Petterson, suggested that the three lanes at Mountbatten Way are wide enough for cars to overtake without switching lanes.